Module Use and Impact The Instrument Shop has two major functions. One function is to design and construct unique instrumentation that is required to fulfill specific needs of investigators. For example, retinal electrophysiologists (Drs. Heckenlively, Hughes, Puro, and Wong) receive substantial benefit from the existence of an Instrument Shop because many of the research instruments and devices they use are not commercially available. The types of instruments that the Instrument Shop routinely fashions for these investigators include perfusion chambers, perfusion controller systems, micromanipulators, Faraday cages, light stimuli, and Ganzfeld bowls. It should be noted that this Module played a vital role in allowing Dr. Wong, who joined the University of Michigan faculty during the granting period, to rapidly set up his electrophysiology laboratory and commence his research. Additional examples of the role of this Module in fabricating unique devices for NEI-supported research included the design and construction of an environmentally-controlled dark adaptation box for Dr. Heckenlively, a unique chamber with a heated base for confocal imaging used by Dr. Hitchcock to study the zebrafish retina, and a specialized elastometer for Dr. Hollman's research on lens elasticity. In addition, the Instrument Shop also constructed items such as custom gel box trays, radiation shields and contamination containers, which are used by investigators who use molecular biology and molecular genetics techniques, and various accessories for the zebrafish facilities. A second function of this Module is to maintain and repair existing instrumentation. This is a crucial task that often allows a project to be quickly resumed after a mechanical failure, and is a function used by virtually all participants.